<template>
<div class="right-side" :style="isShow">
  <div :class="'right-side-config-hide ' + isOut">
    <i :class="'iconfont right-side-icon ' + icon" @click="check" />
  </div>
  <div class="setting-container" @click="show">
    <i class="iconfont iconshezhi setting" />
  </div>
  <i @click="backTop" class="iconfont right-side-icon iconziyuanldpi" />
</div>
</template>

<script>
export default {
  name: "BackTop",
  mounted() {
    window.addEventListener("scroll", this.scrollToTop)
  },
  destroyed() {
    window.removeEventListener("scroll", this.scrollToTop)
  },
  data() {
    return {
      isShow: "",
      isOut:"right-side-out",
      icon:"iconyueliang"
    }
  },
  methods:{
    // 回到顶部的方法
    backTop(){
      window.scrollTo({
        behavior:"smooth",
        top:0
      })
    },
    // 为了计算距离顶部的高度，当高度大于100时显示顶部图标，小于100则隐藏
    scrollToTop(){
      const that = this
      let scrollTop = window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop
      that.scrollTop = scrollTop
      if (that.scrollTop > 20) {
        that.isShow = "opacity: 1;transform: translateX(-38px);"
      } else {
        that.isShow = ""
      }
    },
    show(){
      const flag = this.isOut == "right-side-out"
      this.isOut = flag ? "right-side-in" : "right-side-out"
    },
    check() {
      const flag = this.icon == "iconyueliang"
      this.icon = flag ? "icontaiyang" : "iconyueliang"
      this.$vuetify.theme.dark = !this.$vuetify.theme.dark
    }
  }
}
</script>

<style scoped>
.right-side {
  z-index: 4;
  position: fixed;
  right: -38px;
  bottom: 85px;
  transition: all 0.5s;
}
.right-side-config-hide {
  transform: translate(35px, 0);
}
.right-side-out {
  animation: right-sideOut 0.3s;
}
.right-side-in {
  transform: translate(0, 0) !important;
  animation: right-sideIn 0.3s;
}
.right-side-icon,
.setting-container {
  display: block;
  margin-bottom: 2px;
  width: 30px;
  height: 30px;
  background-color: #49b1f5;
  color: #fff;
  text-align: center;
  font-size: 16px;
  line-height: 30px;
  cursor: pointer;
}
.right-side-icon:hover,
.setting-container:hover {
  background-color: #ff7242;
}
.setting-container i {
  display: block;
  animation: turn-around 2s linear infinite;
}
@keyframes turn-around {
  0% {
    transform: rotate(0);
  }
  100% {
    transform: rotate(360deg);
  }
}
@keyframes right-sideOut {
  0% {
    transform: translate(0, 0);
  }
  100% {
    transform: translate(30px, 0);
  }
}
@keyframes right-sideIn {
  0% {
    transform: translate(30px, 0);
  }
  100% {
    transform: translate(0, 0);
  }
}
</style>
